| Obligatory Manifestation of Malt | Cigar City Brewing | American Barleywine | 11.0% |
| Obliteration I | Midnight Sun Brewing Co. | Imperial IPA | 8.5% |
| Obliteration II | Midnight Sun Brewing Co. | Imperial IPA | 8.3% |
| Obliteration III | Midnight Sun Brewing Co. | Imperial IPA | 7.6% |
| Obliteration IV | Midnight Sun Brewing Co. | Imperial IPA | 8.7% |
| Obliteration V | Midnight Sun Brewing Co. | Imperial IPA | 8.2% |
| Obliteration VI | Midnight Sun Brewing Co. | Imperial IPA | 8.5% |
| Oblivex | Tired Hands | Imperial IPA | 9.2% |
| Oblivion | Wicked Weed | Wild Ale | 8.5% |
| Oblivion Ring aged in Spanish Brandy barrels | Modern Times | English Barleywine | 13.0% |
| Oblivion Ring: NOLA Coffee Edition | Modern Times | American Barleywine | 11.0% |
| Oblivious 2022 edition | Brouwerij De Moersleutel | New England IPA | 7.0% |
| Obol | DuClaw | | |
| Obolon Lager | Obolon Brewery | European Pale Lager | 5.2% |
| Obovoid Empirical Stout | Boulder Beer Company | American Imperial Stout | 8.0% |